The 2020 fall equinox will be here on Tuesday (September 22) at 9:30 AM ET (1:30 PM UTC). The equinox announces the coming of autumn, shorter days for the Northern Hemisphere, and cooler temperatures, and the opposite for the Southern Hemisphere.
A planetary scientist developed an animation to illustrate what really is going on with the equinox. He summarize how these event work and their relationships to the solstices. Here is what you need to know.
The Fall Equinox Explained
Equinoxes and solstices are the results of Earth’s axial tilt – the degree to which the planet is shifted to the Sun. The axis around which our planet rotates isn’t straight up and down. It’s actually 23.5 degrees off, and different parts of the planet are exposed to more or less sunlight. That’s why the seasons exist.
It’s also why the Southern and the Northern Hemisphere experience seasons differently. For instance, the Southern Hemisphere is tilted more towards the Sun during winter in the Northern Hemisphere and vice versa.
The axial tilt’s most significant effect comes during the solstices because the Earth is tilted the farthest away from the Sun, while the other is closest. The Northern Hemisphere gets less than nine hours of daylight on December 21, and the Southern Hemisphere, more than 15.
Dr. James O’Donoghue, a planetary scientist, detailed what happens during the summer solstice. He said: “[…] sunlight is most intense as it only has to pass through a short column of atmosphere.” And that’s why in the summer it is so hot.
12 Hours of Sunlight and Darkness
When Earth’s axis isn’t tilted towards or away from the Sun (two times a year), the sunlight hits the Northern and Southern Hemispheres equally, and equinoxes happen. We get an equal 12 hours of sunlight and darkness.
If you were, let’s say, to stand directly on the equator at 9:30 AM ET tomorrow, your shadow would be at its absolute minimum. And the Sun would be almost directly overhead.
I am very passionate about technology, music, and cinematography. Practically, I based all my life on this stuff! My first passion was and still is to write. I’ll bring you news about science, space, and health.